Parking brake light staying lit

[headejm]

The parking brake dash light on my 1970 is staying lit. It flickers a bit and comes on and off slowly but mostly stays on. Totally checked the switch at the emergency brake and everything is functioning properly. No grounding problem at the switch. Any ideas?

[Filthy Filbert]

Been while since I've looked at the wire schematic...

is the light powered full time, and the switch is the ground?  I'd look for a ground somewhere else, maybe the wire has a nick in the insulation somewhere.

[Bullitt-]

Look at your brake distribution block under the master cylinder. There should be a round plug that connects to a switch.  Pull the plug off & see if the light goes out.. 



  This switch is grounded when the system looses pressure. After rebuilding my brake system the dash light was on. My '73 Service Manual says to what I'll call STOMP on the brake pedal to reset the switch... I did & the light went out.

[tparker]

If that doesn't work I would also check under the break pedal. There is a switch there that might need a little adjusting. After that, I'd start checking the wiring.

[headejm]

@Bullitt- Dang, you guys continue to amaze me! 

Yes, the light went out when I disconnected the wire to the distribution block. Glad the problem wasn't in the dash. Now, can you tell me more about your "STOMP" procedure?

[Bullitt-]

@Bullitt- Now, can you tell me more about your "STOMP" procedure?

 
Forcefully & suddenly apply pressure to the brake pedal with your foot.
In my case I had the engine running as I have power brakes.
If this does not correct the problem after a few attempts you will need to disassemble the distribution block for cleaning which will necessitate new seals
https://www.musclecarresearch.com/mopar-seal-kit-1

https://www.musclecarresearch.com/mopar-brake-tube-tee-rebuild

[72RoadRunnerGTX]

It's called the brake differential switch, it will trip when there is a pressure differential between the front and rear hydraulic systems. Look for leaks in your brake lines or hoses. Correct as necessary, blead this system.

[Filthy Filbert]

@Bullitt- Now, can you tell me more about your "STOMP" procedure?

 
Forcefully & suddenly apply pressure to the brake pedal with your foot.
In my case I had the engine running as I have power brakes.
If this does not correct the problem after a few attempts you will need to disassemble the distribution block for cleaning which will necessitate new seals
https://www.musclecarresearch.com/mopar-seal-kit-1

https://www.musclecarresearch.com/mopar-brake-tube-tee-rebuild

The way the "emergency brake leak warning switch" works, is there's a shuttle valve inside that slides back and forth.   If one circuit loses brake pressure from a leak, the pressure on the other side of the switch will push the valve towards the side with the leak, and closes the switch to activate the warning light.   

If the brake system is in good shape, applying maximum brake pressure by stomping fully on the brake pedal will re-center the valve and open the switch, turning off the warning light on the dash.